Laparoscopy is a method for the exploration of the peritoneal cavity wherein a sterile gas is blown or insufflated into the peritoneal cavity through the tubular portion or cannula section. The tubular portion or cannula section of the trocar assembly is connected to a gas source so that the pressure of the gaseous pocket within the peritoneal cavity may be maintained. This gaseous pocket within the peritoneal cavity is known as a pneumoperitoneum.
The visual exploration of the organs within the peritoneal cavity or other areas of the body is carried out by means of an endoscope or a similar device which passes through the tubular portion or cannula section of a trocar assembly after the tubular portion of a trocar assembly has been put in place in an abdominal wall. Similarly, one or more additional cannulas may be introduced into the pneumoperitoneum for the introduction of various tools to allow additional procedures such as biopsies.
The tubular portion or cannula section of the trocar assembly is a particularly important element, because it must pass through the flesh or tissue surrounding the peritoneal cavity without causing any postoperative trauma, yet still provide for anchorage to the abdominal wall. Above all, the tubular portion of the trocar assembly must assure that a seal is formed between the pneumoperitoneum and the atmosphere external to the peritoneal cavity.
Currently, most trocar assemblies are made of metal to facilitate their sterilization and re-use. Specifically, stainless steel is most commonly used. As far as the sealing means within the trocar assembly are concerned, other synthetic materials are used.
In general, the body portion of prior art trocar assemblies consists of a collection of detachable elements which allow access to the sealing means. After the insertion of the trocar assembly into the patient, the sealing means within the trocar assembly becomes contaminated by blood and other secretions. Thus, these prior art trocar assemblies must be disassembled and cleaned before they can be sterilized for reuse. Consequently, in prior art trocar assemblies that may be taken apart for cleaning, some type of connection means, threadable or otherwise, must be provided between the different parts of the trocar assembly. In some newer prior art trocar assemblies, synthetic materials are used in place of stainless steel. In these newer trocar assemblies, the synthetic materials which are used to seal the pneumoperitoneum from the atmosphere are generally not sterilizable. Such materials are described in European Patent Nos. A-564,373 and A-541,970.
The reusable character of the prior art trocar assemblies requires that they be made of expensive materials, or have a complex and expensive design. Complex and expensive designs provide significant drawbacks for the user. These drawbacks are in addition to those drawbacks which result from the cost of cleaning and re-sterilizing the trocar assemblies.
To overcome these drawbacks, it has been found that less expensive disposable trocar assemblies may be used. French Pat. Nos. A-2,691,625 and A-2,694,181 disclose such disposable trocar assemblies. Despite the fact that the trocar assemblies are disposable, it has been found that some medical care personnel attempt to sterilize these disposable trocar assemblies for re-use.
French Pat. No. A-2,691,625 defines the use of a fibrous, synthetic material for making trocar assemblies. This fibrous, synthetic material is used for the manufacture of both the tubular body portion or cannula section of the trocar assembly, and, also the removable perforation device. Thus, the fibrous synthetic material allows for a reduction in the manufacturing cost of the trocar assembly, but it does not prevent reuse of the trocar assembly.
French Pat. No. A-2,694,181 describes, more particularly, the structure of a sealing means in the tubular portion of cannula section of a trocar assembly. This patent does not address the problem of preventing reuse of the sealing means in a trocar assembly.
The object of the present invention is to provide a laparoscopic trocar assembly which is inexpensive to make, provides a seal to prevent the escape of gas back through the trocar assembly, and yet cannot be re-sterilized and used again. Thus, once the trocar assembly is used it should be rendered unusable.